Metallic stair-tread.



UNITED STATES PATENT Fries.

FREDERICK M. MAHON Y, OF TROY, NEW YORK, ASSIGNOR TO THE MAI-IONY MANUFACTURING COMPANY, OF TROY, NEW YORK.

M ETALLIC STAlR-TREAD.

SPECIFICATION forming part of Letters Patent No. 693,143, dated February 11, 1902.

Application filed January 4, 1901. Serial No. 4210 9- m BI-J To all whom it may concern.-

Be it known that I, FREDERICK M. MAHoNY, of the city of Troy, county of Rensselaer,-and State of New York, have invented new and useful Improvements in Metallic Stair Tre'ads, of which the following is a specification.

My invention relates to an improvement in the construction of metallic stair treads, whereby the top surfaces of the latter are prevented from becoming slippery when worn smooth by use; and it consists in the construction of the tread-surface substantially as and for the purpose set forth.

Accompanying this specification to form a part of it there is a plate of drawings containing three figures illustrating the application of my invention with the same designation of parts by letter reference used in all of them.

Of the illustrations, Figure l is a top view of a part of a stair-tread with my invention shown as applied thereto. Fig. 2 is a section taken on the line m as of Fig. 1 through the tread therein illustrated and also through a riser and another tread not shown at Fig. 1. Fig. 3 is a top view of a part of a stair-tread containing my invention with the details of construction shown on a larger scale than in the other figures.

The several parts of the stair-tread thus illustrated are designated by letter reference, and the function of the parts is described as follows:

The letter T designates the tread; R, the rear part of the tread-top, which is divided off into the plain portion P and that portion T having therein produced the diamond-form areas D by the arrangement of angularly-intersecting grooves bordered by two transverse parallel grooves g, which separate the area having this diamond pattern from the front and rear parts of the. tread, respectively.

The letters 0 designate recesses or sinks formed in the top of the treadin front of the diamond form areas D, these recesses or sinks being made to have a greater diameter at the bottom than at thetop and by which construction the sides of the sinks or recesses are caused to taper inwardly toward each ately bordering the sinks intact, as shown at m.

The letter L designates lead that is inserted into each of the sinks 0, so as to fill them, with the upper surface of the lead arranged to be horizontally in line with the top .of the bordering edges 1%, the top surface of the diamond-form areas D, and that of the rear part of the tread designated at P. These sinks or recesses O are made hexagonal in form, with their top openings having a honeycomb form. It is well known that lead being a soft metal takes on no polish by use, and by forming the surface of the tread with the large proportion of lead which I am able to use by my improved construction of the tread makes the use of stairs having treads of hard metal perfectly safe as regards their becoming slippery by being worn smooth. The advantage of supporting a large area of lead surface under a wearing influence is accomplished by the rims m surrounding the sinks O, which act to retain the lead in position as a portion of the top surface of the tread. By making the sinks O of a hexagonal form a much greater area of leaded surface can be utilized than where circular, oval, or elliptical forms of sinks are employed.

While I have named lead as the soft metal to housed in connection with the sinks, it may be usedin connection with another metal as an alloy,'if desired, and while I have shown the sinks and leadas applied to a part of the stair-tread it may, if desired, be applied to the whole of the top.

Having thus described my invention, what I claim, and desire to secure by Letters Patcut, is--- A stair-tread'having a smooth rear part, a honeycombed front part provided with re= cesses for receiving lead and an intermediate part grooved in diamond pattern and having two transverse grooves g separating said-pattern from said front part and rear part sub stantially as set forth. Signed at the city of Troy, New York, this 24th day of November, 1900, and in the presence of the two witnesses whose names are hereto written.

FREDERICK M. MAHONY.

Witnesses:

W. E. HAGAN, W. A. SWEET. 

